How does Tumwater's water compare to the national average?

The USA national average is 151 mg/L. Tumwater (≈ 120–179 mg/L) is 1 mg/L softer than average.

Tumwater Water Hardness & Quality Report (2026)

Water Hardness

hard

~120–179 mg/L

Hard

estimated · not lab-verified

Source

groundwater

pH Level

7.4

neutral = 7.0

Lead

0.005 mg/L

✓ Below action level

TDS

98.9 mg/L

Est. Daily Cost

$0.40

energy & soap waste

Source: See methodology section below · Updated 2026

hard~120–179 mg/LHard · est.

0–60

mg/L

Soft

61–120

mg/L

Moderately Hard

121–180

mg/L

Hard

180+

mg/L

Very Hard

Appliance Damage Report

In Tumwater, your appliances are currently losing 20% efficiency due to mineral buildup.

Appliance	In Tumwater	Soft Water City	Efficiency Loss
Kettle	6.8 yrs	8.5 yrs	-20%
Washing Machine	9.6 yrs	12 yrs	-20%
Water Heater	12 yrs	15 yrs	-20%

Regional Water Comparison

How Tumwater compares to its nearest neighbours

City	Hardness	PFAS (ppt)	Risk	Source
▶ Tumwater, Washington	≈ 120–179 mg/L	13.3 ppt	🟠 Hard	groundwater
Olympia, Washington	≈ 120–179 mg/L	26.5 ppt	🟠 Hard	groundwater
Lacey, Washington	≈ 120–179 mg/L	42.3 ppt	🟠 Hard	groundwater
Centralia, Washington	15.5 mg/L	32.4 ppt	🟢 Soft	groundwater
Joint Base Lewis McChord, Washington	38 mg/L	156.7 ppt	🟢 Soft	groundwater

National Benchmark

How Tumwater compares to the USA average

Benchmark	Hardness	Appliance Risk
▶ Tumwater	≈ 120–179 mg/L	🟠 Moderate
USA National Avg	151 mg/L	🟠 Moderate
Scarsdale Top Rated	0.02 mg/L	🟢 None

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What Makes Tumwater's Water Unique?

Local geology and source profile

Source: GroundwaterTDS: 98.9 mg/LpH: 7.4

The City of Tumwater Public Works Department serves Tumwater, Washington, through the Tumwater Water Division. The supply draws from the Deschutes River in Thurston County or from local Thurston County groundwater wells, depending on demand. No named treatment plant facilities, reservoir names, or service area boundary details beyond the city itself were identified in available sources. Treatment process specifics are not available from retrieved data. Residents should contact the utility directly for current water quality reports and service details.

The Deschutes River drains the Black Hills of Thurston County, which are underlain by Eocene Crescent Formation basalt, with the watershed also influenced by the western Cascades foothills. This Puget Trough basalt and Cascade foothills watershed produces very soft water with very low total dissolved solids, as basaltic rocks release few soluble minerals compared to carbonate formations. The resulting supply is characteristically soft due to the non-carbonate volcanic geology of the drainage area.

Very soft water from this basalt watershed means minimal scale buildup in appliances — pipes, water heaters, and dishwashers face little risk of mineral deposits, and washing machine and faucet performance is generally unaffected by limescale. No specific pH, lead/copper compliance, PFAS, or contaminant data was identified in available sources, and treatment process details are not available. Residents should contact the City of Tumwater Public Works Department for current Consumer Confidence Reports and full water quality parameters.

Geology & Source: Thurston County — Deschutes River drains Black Hills Eocene Crescent Formation basalt and Cascade foothills; Puget Trough basalt watershed drainage produces very soft water with very low TDS

Other Washington Water Reports

Olympia

≈ 120–179 mg/L

🟠 Hard

Lacey

≈ 120–179 mg/L

🟠 Hard

Centralia

15.5 mg/L

🟢 Soft

Joint Base Lewis McChord

38 mg/L

🟢 Soft

Report an Issue

Notice an error or missing data? Help us keep this page accurate. If you spot incorrect water hardness, outdated utility info, or missing details, please let us know.

All reports are reviewed by our team. Thank you for supporting data quality!

Frequently Asked Questions

Is Tumwater's water safe to drink?

Yes. Tumwater's water meets all federal safety standards. The hardness is ≈ 120–179 mg/L (Hard), which is safe to drink. High hardness affects appliances and taste, but poses no health risk.

Do I need a water softener in Tumwater?

At ≈ 120–179 mg/L (Hard), Tumwater's water will cause significant limescale on kettles, washing machines, and water heaters. A water softener or descaler is strongly recommended to extend appliance lifespan and reduce energy bills by up to 20%.

How does Tumwater compare to the USA average?

The USA national average is 151 mg/L. Tumwater (≈ 120–179 mg/L) is 1 mg/L below the national average. The softest major city is Scarsdale at just 0.02 mg/L.

Data Sources & Methodology

Water quality data for Tumwater is derived from geographic and geological modelling of the surrounding region. No federal monitoring station data was available for this location.

Estimated

Water Hardness

Modelled estimate based on state-level USGS geological survey data for this region. No direct USGS Water Quality Portal measurement was matched to this city — the value reflects a statistical range calibrated to the state's dominant rock types and typical source water characteristics.

Estimated

Estimated from regional geology and source water characteristics. pH is correlated with water hardness and local bedrock — values may differ from utility-reported figures.

Estimated

TDS — Total Dissolved Solids

Estimated using a derived ratio from water hardness and regional conductance profiles. TDS in natural water correlates strongly with total mineral content including hardness ions.

Measured

PFAS — Perfluoroalkyl and Polyfluoroalkyl Substances

EPA UCMR5 (5th Unregulated Contaminant Monitoring Rule, 2023–2025) — sum of PFAS compounds detected at the public water system serving this city. A value of 0 indicates the system was sampled with no detection above reporting limits.

Modelled

Lead

Modelled estimate based on the EPA Lead and Copper Rule 90th-percentile tap-sample methodology. No publicly available per-city lead dataset with sufficient national coverage exists. Values are a conservative baseline derived from city population tier and infrastructure age — all estimates are maintained below the EPA action level of 0.015 mg/L.

Calculated

Appliance Lifespan

Calculated from water hardness using a linear degradation model. Baseline lifespans represent soft-water performance (kettle: 8.5 yrs, washing machine: 12.0 yrs, water heater: 15.0 yrs). Hard water mineral scale progressively reduces operational life in direct proportion to hardness concentration.